And considering comparisons that have been made with the Donald Trump administration, Balesaid that while the two men are very different, Cheney, who was instrumental in foreign policy decisions in the US after 9/11, "is a part of why we have come to have Trump in charge".

However, he said that while Cheney "has a brain" and understands government, he can't say the same about the president.

"The film, what I love about it, [director Adam McKay's] style finds humour in the most tragic of circumstances - comedy is tragedy plus time, right?" he said. "It's a way to make it palatable without just making you want to shut off.

"He managed to give facts, but real poignancy, real humour to it. I find myself crying with laughter and then bloody crying with absolute sadness for what America could be versus the choices that were made and where we find ourselves nowadays, which to me are the absolute opposite of the high ideals that America should be striving for.

Bale, who lives in California, says there is a "gross partisanship" in the US and that Cheney had contributed to it.

"Absolutely, Cheney is a part of why we have come to have Trump now, in the incredibly sort of gross partisanship that you get here in America," he said.

"He understands government better than Trump ever could. He has a brain on him, he's not constantly boasting about his IQ, he genuinely is a brilliant, ambitious man who really understands how to push the buttons and pull the levers to make government work for him. And understands the power of silence and secrecy and working in the shadows.

"That doesn't describe Trump, does it?

Image:Bale won a Golden Globe for his portrayal of Cheney, and is also nominated for an Oscar

"So they're very opposite in terms of personalities like that, but in terms of the partisanship and in terms of the misleading, wilful misleading of the public with information that leads to actually enormous consequences - not only for America but for the global landscape, for what has happened in the Middle East - if you look back at that then Cheney undoubtedly is absolutely one of the architects of where we find ourselves at as a world right now."

Bale also spoke about his incredible physical transformation for the role, saying that it helped him get into character.

"It makes my job so much bloody easier," he said. "If I can look in the mirror and not see myself, then the job's already half done for me, I don't have to try so hard."

Vice is not the first time Bale has altered his appearance for a role, with The Fighter, American Hustle and The Machinist just a few of the films which have seen him undergo dramatic physical transformations.

Co-star Amy Adams, who plays Cheney's wife Lynne in Vice and also starred alongside Bale in The Fighter and American Hustle, says she often feels like she has only known him in character.

"It's always funny because when I see Christian after the fact, even when we did The Fighter, when we did American Hustle and now again in Vice, whenever I see him months later when we're out promoting the film, I'm always like 'who is this person?' I've only known him in character it feels like at times," she said.

"In this he did something really remarkable because he took a character that is more recognisable, that people know, and he was able to transform himself in a way that allowed access… I would forget what Dick Cheney looked like. I had to go look it up after we were done filming because I could only think of Christian Bale as Dick Cheney."

Bale says his wife Sibi Blazic and children are also now used to his changes in appearance.